Roughly 1,800 neighbors of missing mom Jessie Davis turned out to join professional trackers and police in the search, but once again came up empty-handed, as once was thought to be a potential lead turned out to be a plot for marijuana plants.

Volunteers on Thursday used horses, golf carts and all-terrain vehicles to search through backyards, vacant fields and a Christmas tree farm for Davis. They were told to walk three feet apart, looking for tire marks and fresh dirt.

"You just can't go home and assume somebody will take care of it," said Barb Schollaerd, 51, of North Canton. "We look after our own."

Davis, whose baby is due July 3, was last heard from in a phone call with her mother on June 13. Two days later, her mother checked on her home in nearby Lake Township and found it in shambles, with the furniture overturned, a comforter missing and her 2-year-old grandson wandering around alone.

The little boy told investigators: "Mommy was crying. Mommy broke the table. Mommy's in rug."

Whitney Davis, the missing woman's younger sister, said the boy misses his mother. "He asks where she is," she said.

Authorities have talked with and searched the home of the man who fathered the son of the 26-year-old Davis, although investigators have repeatedly said Canton police officer Bobby Cutts Jr. is not a suspect. Cutts, 30, says he had nothing to do with Davis' disappearance. The woman's family says he is also the father of Davis' unborn baby.

About 1,800 volunteers searched the area around Davis' home for about 4 1/2 hours until the effort was suspended because of heavy rain. Groups of 80 to 100 searchers each covered areas of about eight square miles.

An FBI evidence crew and investigators spent several hours examining a site of freshly dug dirt in a field at the end of a dirt road more than a mile from Davis' home. Family members who were with the team that found the spot embraced when it was discovered.

But the site turned out to be a marijuana plot, about 6-feet long and 3-feet wide, said Stark County sheriff's Capt. Gary Shankle. Investigators responded to the scene because the freshly dug dirt caused a reaction among private search dogs, he said.

"It's very frustrating, but we just can't leave any stone unturned," Shankle said.

Earlier, Whitney Davis, the missing woman's younger sister, said she was amazed by the crowd of volunteers. She wore a T-shirt with her sister's picture and the word "Missing" in red letters.

"I think we're going to find her," she said.

The turnout was the largest of 704 searches by the internationally active group Texas EquuSearch, which brought a remote-control airplane equipped with a camera.

"We've never had that many show up at one time," said EquuSearch director Tim Miller.

His group had expected about 200 volunteers for the search in northeast Ohio. "It's overwhelming. It's almost out of control. But we're going to make it happen," he said early in the day.

One woman wore high heels but gave up 20 minutes later after walking through a wooded area. Another maneuvered on crutches. "I'm here for the whole thing," said Tammy Robinson, 47.

Team leaders were told to look for tire tracks and any debris or other things that appear out of the ordinary. Miller also instructed that if a body was found, the leaders should stay with it and move other searchers away.

"I'm hopeful we can find her alive," he said. "If not, the second best thing we can do is be back here next week for a funeral."

Some volunteers brought their dogs or children. People signing up to help at a fire station formed a line about two football fields long along a sidewalk.

"We're probably looking at somewhat of a miracle in this case," Miller said. "We also know if that person is deceased out there it's very important we find them as quickly as we can find them so they can determine cause of death."

On Wednesday, sheriff's investigators and FBI agents carried out more than a dozen white cardboard boxes, a few brown bags and three large black plastic bags during a search of Cutts' home.

His mother, Renee Horne, told The (Canton) Repository that agents were looking for Davis' cell phone and a quilt missing from her home.

Horne said FBI agents questioned her son twice Wednesday, and read him his Miranda rights during the second interview. Investigators also took Cutts' two cell phones, she said.

Meanwhile, the DNA of a newborn baby found about 45 miles from Davis' home was being tested to see if the infant is related to the missing woman. The testing was not expected to be finished until next week.

Rewards totaling $15,000 are being offered for information leading to Davis' whereabouts.

Police officer Jamie Mizer led one of 14 groups during the search. She is three months pregnant.

"That's kind of what's motivating me to be out here," she said.

The Associated Press contributed to this report.